Hydraulic apparatus



July 25, 1950 w. c. DENISON, JR

HYDRAULIC APPARATUS 3 Sheets-Sheet 1 Filed Sept. 14, 1944 INVENTOR William OJJentsomJr.

ATTORNEY y 5, 1950 w. c. DENISON, JR 5 3 HYDRAULIC APPARATUS Filed Sept. 14, 1944 3 Sheets-Sheet 2 FIG.5.

INVENTOR William C.De1'u',so11,JT.

B Y XZQM'WKW ATTORNEY July 25, 1950 v w, c DENISQN, JR 2,516,301

HYDRAULIC APPARATUS Filed Sept. 14, 1944 3 sheets-sheet' s IN VEN TOR.

William CD611 LsomJr A TTO RNE'Y Patented July 2 5, 1950 William C. Denison, Jr., Powell, Ohio, assignor to The Dcnison Engineering Company, Columbus, Ohio, a corporation of Ohio Applicationseptember 14, 1944, Serial No. 554,019

8 Claims.

v This invention relates tomachinery and isparticularly directed to presses and similar appa- =ratus..

. Oneof the objects of this invention is to provide a compact hydraulic press unit which is characterized by its simplicity, the slight numberv of movingparts and thelack of connecting pipes and tubes. I.

Another object of the invention .is to provide a hydraulic press with parts so constructed :and arranged that a minimum quantity of hydraulic fluid will be required in the operation of the press and the resistance heretofore caused by long restricted conduits will be practically eliminated, thereby reducing the power required to actuate the press.

A further object consists in providing a hydraulic press with a frame having a reservoir in which a pump is positioned and securing a head to the frame at one side of the reservoir, the head having a port which registers with the outlet of the pump in the reservoir, a conductor having its ends disposed in the port and the pump outlet, slip joints only being employed between the conductor and the various other parts.

Another object of the invention is to provide a hydraulic presshaving a frame with a forwardly projecting platen, a motor chamber, a reservoir above the chamber and a head mounted on the frame above the platen, the head being formed with a ram cylinder and passages connecting the ram cylinder with a control valve cylinder which in turn is connected with the reservoir and a pump positioned in the reservoir and operatively connected with a motor located in the motor chamber. 1

An object also is to provide a hydraulic press having an integral head formed with communicating piston and valve cylinder, the latter of which communicatesalso with spaced inlet, outlet and work ports, valve means being slidably disposed in the valve cylinder to control communication between the various ports and fluid flow to and from the piston cylinder, the head also being provided with a by-pass connecting the inlet and an outlet, the by-pass receiving a resiliently biased valve so that excess pressure in the inlet port will be vented to the outlet before the various parts of the press can be injured by high pressure.

It is another object of the. invention to provide a fluid pressure operated press having a head with piston and valve cylinders formed therein, the valve cylinder communicating at spaced points with inlet, outlet and work ports,

the latter ports being connected with the piston cylinder by passages formed in the head, a valve being-slidably disposed in the valve cylinder to control fluid flow between the various ports to effecttheoperation of the piston in its cylinder,

a connection being provided between the piston and the slidable valve so that the latter will-be operated by the former and continuous operation of the press "may besecured if desired.

An object also-consists inproviding the press mentioned in the preceding paragraph with mechanism for manually operating the valve so that operation of the press can be initiated and discontinuedatwill. Further objects and advantages of the presen invention willbe apparent'from the following description, reference being bad tothe accompany:- ing. drawings wherein a preferred formof embodiment of the invention is clearly shown.

Inthe drawings:

Fig. 1 is a vertical sectional view taken through a press' formed in accordance with .the present invention; a

Fig. 2 is a detailed vertical sectional :view taken through the controlirmechanism ofthe press on the plane indicated by the line 2-2 of Fig.1 and shows this control mechanism in condition to maintain the press inactive; 1

Fig. 3 is a similar view taken-on the plane in- .dicated by the line 3--.3 of Fig. 2-.and' shows the control mechanism in condition to cause .the press'toperform a working. stroke;

Fig. 4- is a similar view showing 'thecontrol mechanism in condition to return the ram of the press .to-aninitial ,or'starting. position; and

Fig. 5 is a detailed horizontal sectional vie'w taken through the control mechanism on vthe plane'indicated by the line 5".5. of Fig. 2.

Figure 6=is a diagrammatic view showing the hydraulic system and associated parts employed in-the press disclosed-in Figure'l in the drawing.

Referring. more particularly to r the :drawing, .the numeral 20 designates .the press in its entirety. In theformaof theinv'ention shown, the press=:20 includes a frame 2-! which preferably of cast metal and includes platen-122 and upright body 23-at the back-.of -the platena22. The body .23 includes a front wall 24 andside walls-25. Atithe upper portion of the body. 23, ahorizontalzwall 26 projects lrearwardly from :the 'wall 24' andtconnects with the lower end of a rear wall 27, the upper portions of wallsZl and 25 and the walls Hand 21; cooperate to form a chamber 28;.the purpose of which-will be setforth hereafter. The body 23x andthe platen 22 form a substantially L-shaped frame which is rigid and capable of withstanding the loads imposed thereon during the operation of the press.

The lower portion of the body 23 is open at the back to permit the installation of an electric motor 30, this member being secured to the rear of the wall 24 by screws 3| or other fastening elements. The armature shaft 132 of the motor is connected by a coupling 33 with the operating shaft 34 of a hydraulic pump 35. This latter member is positioned in the chamber 28 and is secured to a pad 36 surrounding an opening 31 formed in the wall 26 in registration with the axis of rotation of the motor 30. Suitable sealing gasket means 38 are disposedbetween the pump and the wall 26 to prevent the escape of fluid from the chamber 28 into the space occupied by the motor 30.

The inlet of the pump 35 is provided with an elbow 40, the open end of which is turned downwardly toward the bottom of the chamber 28 to insure a supply of fluid for the pump in the event the level should fall in the reservoir. The outlet 4! of the pump includes a boss 42, having an opening 43 into which the end of a tube 44 is inserted; this tube has its opposite end projecting through an opening 45 in the wall 23 and into the open end 46 of a duct 41, formed in ahead casting 48 secured to the upper end of the front wall 24. As illustrated in Fig. 5, the end portions of the tube 44 are provided with annular grooves 58 to receive resilient rings which are compressed between the outer wall of the tube 44 and the inner walls of the opening 43 and duct 41 to seal the joint between the tube and these elements and thus prevent the escape of fluid. The surface of the head 48 which engages the wall 24 is provided also with grooves around the open end of the duct 41 and a return duct 52 for the reception of compressible sealing rings to prevent the escape of fluid at these locations.

After the head 48 has been secured to the body 23, the chamber 28 may be filled with hydraulic fluid through an opening provided in the top wall 53 of the body. This opening is normally closed by a cover 54 secured to the wall 53 by screws 55. An inlet fitting 56 is also provided in this top wall to permit the addition of fluid without removing the cover 54. suitable cap means 5'. covers the fitting .56 to prevent the entrance of dirt or other foreign material.

The head 48 is provided with a vertically extending cylinder 58 for the slidable reception of apiston 6|. This piston has a ram 62 projecting from its lower end through an opening 63 provided in a cap 84 which closes the open lower end of the cylinder 58. The head is also provided with a pair of ducts 65 and B6 communicating with the lower and upper ends, respectively, of the cylinder 58. These ducts B5 and 86 extend to vertically spaced chambers 61 and 68 which communicate with the duct 41 so that fluid under pressure from pump 35 may be directed to the piston cylinder 58. The cylinder II also communicates with the return duct 52 to permit fluid to be conducted from the cylinder 58 back to the chamber 28, this chamber constituting a reservoir for the hydraulic fluid. The duct 41 terminates at its inner end in a chamber which is disposed between the chambers El and 68, while the duct 52 is connected by vertical branches I2 with a pair of chambers 13 and 14 communicating with the cylinder H at opposite sides of the chambers 81 and 68 from chamber 18.

To control the flow of fluid between the cham- 4 bers 61, 68, I8, 13, and 14, the cylinder H slidably receives a spool valve 15. This spool valve comprises a barrel member having a plurality of annular grooves 16, TI, and 18 spaced longitudinally thereof. The upper end of the barrel is provided with a head 8|] which serves to limit the downward sliding movement of the valve 15 in the cylinder H. When the valve 15 is disposed in the position shown in Fig. 2, the unreduced portions 8! and 82 between the grooves 16, ll,

'and 18 will prevent communication between the chamber 10 and chambers 81 and 68; they will also prevent communication between the latter two chambers and chambers 13 and 14, thus trapping fluid in the cylinder 58 on both sides of the piston 6|. The piston and ram will, therefore, be restrained against movement. When it is desired to have the piston and ram 61 and 62 perform a working stroke, the valve 15 is moved upwardly to the position shown in Fig. 3. Movement is imparted to the valve through the operation of'a control lever 83, the lever being depressed at the forward portion of the platen to cause the rear end and a rod 84 connected with it to move upwardly. The upper end of this rod is connected with a spring cup 85 which is also connected to the lower end of the valve 75. A compression type coil spring 88 is disposed between the inner end of the cup 85 and the bottom wall of the head 48 to urge the valve 15 to its lowermost position therein; an enlargement 88 at the upper end of the valve 15 engages the upper wall of the member 48 to limit the downward movement thereof.

When the valve 15 has been elevated to the position shown in Fig. 3 communication will be established between chamber In and chamber 68, thus permitting fluid under pressure to flow from pump 35 through tube 44, chambers 10 and 88,

and duct 66 to the upper end of cylinder 58'.

This fluid will exert a downward force on the upper end of piston 8| causing it to move downwardly. The fluid in the lower portion of cylinder 58 will then flow through duct 65, chamber 51, groove 18, and duct 12 and 52 to the reservoir 28.

As long as the operating lever 83 is held in its depressed position, the piston and ram 6! and 62 will move downwardly or exert a downward force on an article of work disposed on the platen 22. Means have been provided to reverse the direction of travel of the piston and ram at the lowermost end of their travel, this means constituting a collar 81 adjustably secured to the rod 84. This collar is engaged by a fork 88 which is secured to and moved by the ram 82. As the ram approaches the lower limit of its travel, the fork 88 will engage the collar 81 and force the rod 84 downwardly. Since this rod is connected with the valve 15 through the spring cup 85, downward movement will be imparted to the valve causing it to assume the position shown in Fig. 4. This position will also be assumed by the valve if the operating lever is released at any time during the operation of the machine. When the valve is disposed in its lowermost position, fluid will flow from chamber 18 through chamber 81 and duct 65 to the lower portion of cylinder 58 beneath piston 6|. The force thus applied to the piston will cause it to move upwardly and force the fluid above the piston out through duct 65, chambers 68 and 14, and ducts l2 and 52 to the reservoir 28. This upward movement of the piston will continue until the fork 88 engages a second collar 98 also carried by rod 84. Continued movement of the ,piston and ram after. this engagement will cause the rod at to move thevalve l5, upwardly until the valve occupies the position shown in Fig. 2 wherein theiflow of fluid to and from the cylinder 58 will be discontinued. The piston and ram will then be in an elevated initial position as shown in Fig. 1 ready to start another cycle of operation. I

When the valve 55 is disposed to prevent fluid flow to and from the cylinder 58, fluid under pressure must be returned to the reservoir to prevent the building of excessive pressure in duct 4? and chamber it. A -by-pass 92 is, therefore, provided which extends, as shown in Fig. 2, from the duct 4'. upwardly and laterally to the chamber M. The by-pass 92 has an insert 93 positioned .therein for engagement by a valve 94 to prevent undesired flow of fluid therethrough. The valve 9i,- is yieldably urged toward the seat insert 93 by a coil spring 95 having one end arranged. in a recess formed in the valve. and a socket 86 formed in an adjusting screw 91. This screw is adjustably received by the upper end of a boss 98 formed on the head 48 at one side of the cylinder H. Through the adjustment of the screw 31, the tension of spring 95 may be varied to control the pressure at which fluid will be vented to the reservoir. The adjustment of this spring will also determine the maximum pressure exerted by the ram in the operation of the machine since, when the ram is engaged with an article, the fluid is being directed to the upper end of the piston 6i and the force of this fluid will also be applied to the valve 94. When the pressure for which spring 95 has been adjusted is reached, valve 9i will operate to permit fluid to be by-passed from the inlet to the outlet and the ram 62 will then be exerting its maximum force.

From the foregoing, it will be apparent that a bench press has been provided which is compact, has a minimum number of moving parts as well as a minimum number of fluid connections. A novel method of conducting fluid from the hydraulic pump to the power unit has been provided and the press will, therefore, require slight attention to maintain it in operation.

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

I claim:

1. A bench press comprising, in combination, an L-shaped frame having a platen, a motor chamber and a reservoir above the motor chamber; a head on said frame over said platen, said head having a cylinder; piston means disposed in said cylinder for sliding movement toward and away from said platen; a motor in said motor chamber; a pump in said reservoir and operatively connected with said motor; and means for controlling fluid flow between said pump and said cylinder and between the latter and said reservoir.

2. A bench press comprising, in combination, an integral frame having a platen, a motor chamber and a reservoir over said motor chamber; a unitary head on said frame over said platen, said head having a pair of cylinders connected by passages, one of said cylinders being in open communication with said reservoir; a piston disposed in the other cylinder for sliding movement toward and away from said platen; a motor in said motor chamber; a pump mounted insaid reservoirandoperatively connected with said motor; means connecting the outlet of-zsaid pump with the first cylinder in said head; and means in said first cylinder for controlling'fluid flow to and from the other cylinder,

3. A bench press comprising, in combination, an L-shaped frame having a platen, a motor chamber and a reservoir above themotor chamber; a head on. said frame over said platen, said head having a pair of cylinders, one of.-said cylinders having spaced inlet, outlet and work ports communicating therewith, said head forming passages connecting said work. ports with spaced portions of the other cylinder and said outlet ports with. said reservoir; piston..means disposed in thesecond cylinder for sliding-move.- ment toward and away from said .platen; apump disposed in said reservoir; a motor mounted. in

said motor chamber and operatively connected with said pump; and means in the ffirst cylinder in said head for controlling communicationber tween the inlet, outlet and work ports. I i

4. A bench press comprising, in combination, an L-shaped frame having a platen, a motor chamber and a reservoir above the motor chamber; a head on said frame over said platen, said head having a pair of cylinders, one of said cylinders having spaced inlet, outlet and work ports communicating therewith, said head forming passages connecting said work ports with spaced portions of the other cylinder and said outlet ports with said reservoir; piston means disposed in the second cylinder for sliding movement toward and away from said platen; said piston means having a ram projecting toward said platen; a pump disposed in said reservoir; motor means mounted in said motor chamber and operatively connected with said pump; means in the first cylinder in said head for controlling communication between the inlet, outlet and work ports; and means movable with said ram for actuating said controlling means.

5. A bench press comprising, in combination, an L-shaped frame having a platen, a motor chamber and a reservoir above the motor chamber; a head on said frame over said platen, said head having a pair of cylinders, one of said cylinders having spaced inlet, outlet and work ports communicating therewith, said head forming passages connecting said work ports with spaced portions of the other cylinder and said outlet ports with said reservoir; piston means disposed in the second cylinder for sliding movement toward and away from said platen, said piston means having a ram projecting toward said platen; a pump disposed in said reservoir; motor means mounted in said motor chamber and operatively connected with said pump; means in th first cylinder in said head for controlling communication between the inlet, outlet and work ports; means movable with said ram for actuating said controlling means; and manually operated means for actuating said controlling means independently of said ram operated means.

6. A press comprising, in combination, a frame having a platen, a reservoir above said platen; a head on said frame in vertical registration with said platen, said head having piston and valve cylinders, the latter communicating with inlet, outlet and work ports, said head forming passages connecting said work ports with said piston cylinder and said outlet ports with said reservoir; a pump disposed in said reservoir; and a duct extending between the outlet of said pump and the inlet port in said head.

. '7. A press comprising, incombination, a frame forming a reservoir a head with piston and valve cylinders-secured to said frame, said head having inlet, outlet and work ports communicating with said valvecylinder; passageways formed in said head to establish communication between said work ports and the end portions of said piston cylinder; and said outlet ports and said reser- :voir; a pump disposed in said reservoir with its outlet in registration with the inlet port in said head; and a duct extending between said pump outlet and said inlet port.

8. ma bench press, a frame having a platen, amotor chamber, a motor in said chamber, and a reservoir at one end of said motor chamber, said reservoir having spaced openings in a wall thereof; a fluid pump in said reservoir and con- .nected with said motor, the outlet of said pump communicating with one of the openings in said reservoir wall; a head secured to said frame over said platen, said head having a piston cylinder, a valve cylinder and passages connecting the same, said head having inlet and outlet ports communicating with said valve cylinder and the spaced openings in said reservoir wall; and piston means in said piston cylinder.

WILLIAM C. DENISON, JR..:

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 576,616 Roseman Feb. 9, 1897 898,505 Prouty Sept. 15, 1908 1,692,771 Ferris Nov. 20, 1928 1,775,613 Ferris Sept. 9, 1930 1,855,434 Vickers Apr. 26, 1932 1,904,864 Jongedyk Apr. 18, 1933 2,283,792 Cole May 19, 1942 2,296,051 Pocock et al Sept. 15, 1942 2,319,232 Holmes et a1. May 18, 1943 2,327,079

Wacker Aug. 17, 1943 

